Explosion: equal momenta, unequal energies
"Explosion: equal momenta, unequal energies" is a free, interactive Class 11 Physics simulation for NEET and JEE, built on the NCERT section "Conservation of momentum" in Laws of Motion. A body at rest splits into two pieces; momenta are equal and opposite, speeds and kinetic energies split in inverse ratio of masses. NEET has asked about this idea 1 time in 10 years of papers. JEE Main asked 39 questions from this chapter across the 42 shifts Lumi has analysed (2017–2026).
From the lesson Conservation of momentum in Laws of Motion. Change the values and watch what happens.
What it shows
NCERT § Conservation of Momentum
A body at rest splits into two pieces; momenta are equal and opposite, speeds and kinetic energies split in inverse ratio of masses.
Controls
3 to try
- Slidermass ratio m₁:m₂ 1:1–1:20
- Sliderenergy released 10–500 J
- Togglegun and bullet / bomb / skater throws ball
Try this
Set a gun 400× the bullet's mass and find what fraction of the energy the gun gets (≈0.25 %).
Common mistake
Equal momenta mean equal kinetic energies; using relative speeds in momentum conservation.
In NEET
10 years of papers
Asked 1 time in 10 years of NEET.
See the past questions: Newton's Laws of Motion, Laws of Motion (chapter)
In JEE Main
42 shifts analysed
39 questions from Laws of Motion across the 42 JEE Main shifts Lumi has analysed (2017–2026).
The idea behind it
NCERT § "Conservation of Momentum"
- For an isolated system of interacting particles, total momentum stays constant; this follows directly from the second and third laws.
- Recoil of a gun: gun and bullet start at rest, so after firing their momenta are equal and opposite; the heavier gun moves back much more slowly.
- In any collision the momentum lost by one body equals the momentum gained by the other, whatever happens to the kinetic energy.
- When one body throws another (for example a person on smooth ice throwing a ball), velocities must be measured relative to the ground before applying conservation.
- Momentum is conserved as a vector; in one-dimensional problems keep track of direction with signs.
Questions
5 answers
- What does the "Explosion: equal momenta, unequal energies" simulation show?
- A body at rest splits into two pieces; momenta are equal and opposite, speeds and kinetic energies split in inverse ratio of masses.
- What mistake does the "Explosion: equal momenta, unequal energies" simulation fix?
- A common mistake it clears up: equal momenta mean equal kinetic energies; using relative speeds in momentum conservation.
- Has NEET asked about this idea?
- Yes. NEET has asked about this idea 1 time in 10 years of papers.
- Does JEE Main ask questions from Laws of Motion?
- Yes. JEE Main asked 39 questions from this chapter across the 42 shifts Lumi has analysed (2017–2026).
- Is this simulation free?
- Yes. It is free and runs in the browser on a phone or a laptop. It belongs to the lesson "Conservation of momentum" in Laws of Motion (Class 11 Physics).
Embed this simulation
Free, with a link back
Teaching this idea? Put the simulation on your own page or LMS with this code.